Do I need a money transmitter license if I collect money on behalf of someone in another country (e.g., Ghana) and pay them out monthly to reduce micro-transaction fees?

This makes you an intermediary, when you cited on behalf of a person, implies you are neither the owner of the transaction, nor the recipient and hence this makes you an intermediary, and where ever you go, in most countries this would classify you as a money transfer business and thus require you to get licensed.